This disclosure relates to imaging members and, more specifically, to imaging members having a modified surface layer possessing excellent resistance to wear and reduced formation of laterally conductive deposits that could lead to lateral charge migration print defects.
Imaging members, i.e., photoreceptors, can take several forms including flexible belts, rigid drums, plates, and the like. Electrophotographic photoreceptors can be prepared with either a single layer configuration or a multilayer configuration. Multilayered photoreceptors may include a substrate support, an electrically conductive layer, an optional charge blocking or hole blocking layer, an optional adhesive layer, a charge generating layer, a charge transport layer, an optional protective or overcoating layer and, in some belt embodiments, an anticurl backing layer. In the multilayer configuration, the active layers of the photoreceptor are the charge generation layer (CGL) and the charge transport layer (CTL).
Lateral charge migration (LCM) is one problem which can result from the repetitive cyclic use of photoreceptors. LCM on photoreceptor surfaces results in line and halftone dot growth and a general streaky print appearance. LCM is caused by a thin conductive film which forms on the photoreceptor surface after repeated use. Photoreceptor filming by developer material components initiated by cleaner brush fiber strikes is one factor contributing to the formation of a laterally conductive film. The latter filming is a collection point for conductive species generated by the charging devices. Conductive species are formed when volatile organic contaminants (VOC) in the air combine with ozone/nitrogen oxide/nitric acid emissions from corona charging devices utilized in xerographic print engines. The combination of VOC and ozone/nitrogen oxide/nitric acid emissions and photoreceptor filming can lead to the formation of the laterally conductive films on the photoreceptor surface that lead to LCM print defects.
As the longevity requirements of photoreceptors increases, the development of LCM defects become a problem, especially where the photoreceptor is placed in an environment having VOC contamination, even in those cases where the contamination is only in the parts per billion (ppb) range. The life of a photoreceptor in these environments may only be about 30,000 pages (30 kP), and the only known solution to overcome the LCM defect is to replace the photoreceptor.
Photoreceptors having low sensitivity with respect to laterally conductive film deposits are thus desirable.